Doing a quick search came up with the XAPP itself:
The XAPP369 is dated from 12/2001 so the part it's for, CoolRunner, is obsolete and is no longer produced hence the XAPP for it has been removed from Xilinx's web site also all supporting files have been removed from Xilinx's web site. You're only likely recourse is to speak with your Xilinx FAE and request a copy of the XAPP369 source code files.
You may be better off just searching for another MIL-STD-1553 bus analyzer instead of trying to get the coolrunner design.